As a device for automatically measuring a position of a measurement target, an automatic surveying instrument has been known in the past, which comprises an automated total station comprising a distance measuring unit.
Referring to FIG. 7, description will be given below on a conventional type automatic surveying instrument.
A base unit 2 is disposed on a leveling unit 1. A frame unit 4 is mounted on the base unit 2 via a horizontal rotation shaft 3 so that it can be rotated in a horizontal direction. A body tube 6 is mounted on the frame unit 4 via a vertical rotation shaft 5 so that it can be rotated in a vertical direction.
A horizontal rotation gear 7 is mounted on the horizontal rotation shaft 3, and a horizontal rotating motor 8 is mounted on the base unit 2. A horizontal rotating driving gear 9 is engaged on an output shaft of the horizontal rotating motor 8, and the horizontal rotating driving gear 9 is engaged with the horizontal rotating gear 7. A horizontal angle detecting encoder 11 is provided between the horizontal rotation shaft 3 and the base unit 2.
The frame unit 4 is rotated in a horizontal direction by the horizontal rotating motor 8 via the horizontal rotating driving gear 9 and the horizontal rotating gear 7. A rotation angle is detected by the horizontal angle detecting encoder 11.
A vertical rotating gear 12 is engaged on the vertical rotation shaft 5. A vertical rotating motor 13 is mounted on the frame unit 4. A vertical rotating driving gear 14 is mounted on an output shaft of the vertical rotating motor 13, and the vertical rotating driving gear 14 is engaged with the vertical rotating gear 12. A vertical angle detecting encoder 15 is provided between the vertical rotation shaft 5 and the frame unit 4.
The body tube 6 is rotated in a vertical direction by the vertical rotating motor 13, and an angle in a vertical direction is detected by the vertical angle detecting encoder 15.
In the body tube 6, there are provided a collimating telescope 16, a distance measuring unit (not shown), and a tracking means for tracking a prism reflector (an object to be measured) installed on a measurement target. In the frame unit 4, there are provided a tilt sensor (not shown) for detecting tilt, the horizontal rotating motor 8, the vertical rotating motor 13, a control unit (not shown) for driving and controlling the distance measuring unit (not shown), an operation unit for operating the surveying instrument, a display unit (not shown) for displaying operating conditions, measurement results, etc., and a battery (not shown) for supplying electric power to the control unit, the horizontal rotating motor 8, and the vertical rotating motor 13.
In the conventional type surveying instrument as described above, as a construction for acquiring an image data in a collimating direction, an image sensor (not shown) is mounted on an ocular element of a collimating telescope 16 of the body tube 6 so that an image obtained through the collimating telescope 16 is outputted as an electric signal by the image sensor.
While monitoring a signal from the horizontal angle detecting encoder 11, the control unit drives the horizontal rotating motor 8 and rotates the frame unit 4 in a horizontal direction. While monitoring a signal from the vertical angle detecting encoder 15, it drives the vertical rotating motor 13 and rotates the body tube in a vertical direction. The collimating telescope 16 is collimated in a predetermined direction. A distance to the object to be measured is measured, or a data of an image around the measurement taget is acquired.
In recent years, there have been growing demands on the needs for the image data in association with the distance measuring data. For instance, the distance measuring data is displayed together with the image of the measuring point in order that the measuring point can be visually identified. Further, not only the image of the measuring point but also the image around the measuring point is often required. In addition, there are also demands on the needs for the distance measuring data using the image data as positional data by making the acquisition of the image data as the primary purpose.
The conventional type automatic surveying instrument basically performs measurement by accurately collimating the measurement target. The image data obtained by the conventional type automatic surveying instrument is acquired through the collimating telescope 16. It is the image within a very limited range including the measurement target, and it is a secondary data relating to the measuring point.
Further, the conventional type automatic surveying instrument performs surveying operation by collimating the measuring point one by one, and it is difficult to acquire the data by quickly changing the measuring point. When the measuring point is changed, it is impossible to continuously acquire the image during the process of change.
The continuous image data is often required when a bird's eye view image is to be prepared. In such case, the automatic surveying instrument must be installed at a position higher than the ground surface. In the conventional type, the data necessary for operating the automatic surveying instrument such as measuring condition, data acquiring condition, etc. must be directly inputted to the surveying instrument. The surveying operator must go up each time to a point where the automatic surveying instrument is installed, and it has been inconvenience.
Under the above circumstances, it is an object of the present invention to provide a surveying instrument, by which it is possible to acquire continuous image data in wider range and which has high maneuverability and good working efficiency.